Biodegradable fixation systems could reduce or delete the problems associated with metallic systems, since removal is not necessary. The aim of this study was to establish the effectiveness and safety of biodegradable plates and screws as potential alternatives to metallic ones. This multi-center randomized controlled trial was conducted from December 2006 to July 2009. Included were patients who underwent mandibular and/or Le Fort I osteotomies and those with fractures of the mandible, maxilla, and zygoma. The patients were assigned to a titanium control group (KLS Martin) or to a biodegradable test group (Inion CPS). The primary outcome measure was 'bone healing 8 weeks post-operatively'. The Intention-To-Treat (ITT) analysis of 113 patients in the titanium group and 117 patients in the biodegradable group yielded a significant difference (p < 0.001), primarily because in 25 patients (21%) who were randomized to the biodegradable group, the surgeon made the decision to switch to titanium intra-operatively. Despite this 'inferior' primary outcome result, biodegradable plates and screws could be safely used when it was possible to apply them. The benefits of using biodegradable systems (fewer plate removal operations) should be confirmed during a follow-up of minimally 5 years (Controlled-trials.com ISRCTN number 44212338).